The invention relates to an arrangement for sucking-off gases; such arrangement is particularly suitable for sucking-off air from a steam turbine condenser.
A number of solutions for sucking-off gases are known. These can be generally divided into arrangements operating convectionally and arrangements operating by volume quantities. Convectional arrangements usually are provided with one or several jets of a working liquid, which liquid is conveniently mixed with the gas and, due to the momentum of the working liquid of the transmitted mixture, this mixture is brought to a higher pressure level, which level with arrangements operating like exhaustors is usually atmospheric pressure.
Another example of a convectional arrangement for conveying gases is a channel with an annular hydraulic pump used with arrangements wherein for the mixing a large interphase surface between the gas and water is required, as for instance in the aeration of water in the outlets of water dams.
In recently proposed arrangements operating by volume quantities for sucking-off gases, a solution with a rotating sealing water annulus and an eccentrically rotating system of working chambers is known.
All of the above-mentioned arrangements have some drawbacks. Convectionally operating arrangements have a low efficiency; such efficiency can be defined as the ratio between the product of the gas mass passage and of the difference of pressure potentials in spaces between which the gas is conveyed and the product of the mass passage and the required pressure potential of the working liquid. Drawbacks of arrangements operating by volume quantities are the relatively difficult access to them and their high investment costs.